CyberSecBulletin
CVE-2026-86858NVD status: Awaiting Analysis

ServiceNow AI Platform: Improper Access Control

Published Updated By the CyberSecBulletin desk

CVE-2026-86858 is a high-severity improper access control vulnerability in ServiceNow AI Platform from ServiceNow, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions Yokohama Patch 13 Hot Fix 5a, Zurich Patch 10 Hot Fix 3b, Zurich Patch 10 Hot Fix 4a W32 as the first without the flaw, so updating ServiceNow AI Platform to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.28% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update ServiceNow AI Platform to Yokohama Patch 13 Hot Fix 5a or Zurich Patch 10 Hot Fix 3b or Zurich Patch 10 Hot Fix 4a W32 or Zurich Patch 11 Hot Fix 3, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
ServiceNowServiceNow AI Platformbefore Yokohama Patch 13 Hot Fix 5a; before Zurich Patch 10 Hot Fix 3b; before Zurich Patch 10 Hot Fix 4a W32; before Zurich Patch 11 Hot Fix 3; before Australia Patch 2 Hot Fix 4b W32; before Australia Patch 4 Hot Fix 3; before Australia Patch 5Yokohama Patch 13 Hot Fix 5a, Zurich Patch 10 Hot Fix 3b, Zurich Patch 10 Hot Fix 4a W32, Zurich Patch 11 Hot Fix 3, Australia Patch 2 Hot Fix 4b W32, Australia Patch 4 Hot Fix 3

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
NoneNo loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (servicenow.com).

Official description

ServiceNow has remediated an improper access control security issue that was identified in the ServiceNow AI Platform. This security issue could enable an unauthenticated user, in certain circumstances, to create, modify, or delete instance data beyond what was intended. In August 2026, ServiceNow deployed a security update to hosted instances and ServiceNow provided the update to our partners and self-hosted customers. We are not currently aware of malicious exploitation against ServiceNow instances. We recommend customers promptly apply appropriate updates or upgrade to a patched release if they have not already done so.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Improper Access Control vulnerabilities (CWE-284)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).

References

Other vulnerabilities in ServiceNow AI Platform

All ServiceNow AI Platform vulnerabilities

Recent Improper Access Control vulnerabilities

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